Fig. 3. Schematic right lateral view of the major epaxial muscles of the brown tree snake at mid-body. SSP-SP, semispinalis-spinalis muscle; M, multifidus muscle; LD, longissimus dorsi muscle; IL iliocostalis muscle. The colored areas indicate contractile tissue, the tendons are white, and the skeletal structures are gray. Vertebrae are numbered beginning at the anterior attachment site of a single segment of the SSP-SP, and five vertebrae (3–7) are not shown. The thin horizontal line represents the shelf formed by the pre- and postzygapophyses.